粉煤灰水泥土力学特性试验研究

Experimental Studyon the Mechanical Properties of FlyAsh Cement Soil

针对上海苏州河区域的软土特点,将粉煤灰和水泥作为固化材料加固饱和软黏土,研究粉煤灰对水泥土力学特性的影响.通过无侧限抗压强度试验,研究了不同粉煤灰掺量、水泥掺量以及不同龄期对水泥土强度和变形特性的影响;通过Matlab数据拟合,提出了水泥粉煤灰固化土的强度预测方法.随着龄期的增长和粉煤灰掺量的增加,固化土的应力应变关系由塑性破坏转变成脆性破坏.当粉煤灰掺量过高时,水泥土中易发生耦合反应,影响固化效果.因此,水泥掺量与粉煤灰掺量比例为1∶1,且粉煤灰最佳掺量为14%~18%.

Based on the soft soil characteristics of the Suzhou River in Shanghai,the saturated clay with fly ash and cement as solidified materials was used to research the effect of fly ash on the mechanical characteristics of cement soil.Through unconfined compressive strength tests under different cement dosage,fly ash and curing time,the mixing soil strength properties and deformation characteristics were investigated and a prediction method for the relation between unconfined compressive strength and curing period was proposed through the data fitting by using the Matlab.The results show that the stress strain relationship of the stabilized soil will be changed from the plastic collapse intobrittle failure with the increase of fly ash and the age.When the fly ash dosage is too high,the coupling reaction is likely to occur,which affects the solidified effect.The best content ratio of cement to fly ash is1∶1,and the optimum amount of fly ash is from14%to18%.